The emergency treatment of cardiac anomalies, involving defibrillation or monitoring of the electrical activity of a patient's heart may place a great deal of stress on medical personnel. For example, when a patient experiences cardiac arrest, the responding personnel are expected to quickly and accurately connect defibrillation electrodes to a defibrillator/monitor, apply the electrodes to the patient's chest area, and use the defibrillator/monitor to determine a further course of action. At times, the patient's life depends on the speed and skill with which these tasks are performed.
Reviewing the sequence of steps typically involved in this process in greater detail, cable leads included with the defibrillator/monitor are first attached to electrode pads. The cable leads are usually attached to the electrode pads before the pads are applied to the patient's chest to avoid the patient discomfort that might otherwise occur if the cable leads were pressed onto pads already attached to the patient.
Next, the electrode pads are applied to the patient's chest. As will be appreciated, the proper placement of the pads is an important factor in the successful achievement of defibrillation. In that regard, the pads should be positioned to ensure that the heart is in the current path defined between the pads. Also, the distance of the pads from the heart and their positions with respect to relatively nonconductive elements, such as the patient's sternum, should be selected to ensure that the impedance between the pads does not unduly limit the current applied to the heart.
One conventional electrode placement is referred to as an anterior/anterior arrangement. In this configuration, one pad is positioned lateral to the patient's upper sternum and below the patient's right clavicle. The second pad is placed on the patient's lower left chest, below and lateral to the cardiac apex. The anterior/anterior configuration is often used because of the ease with which the pads can generally be applied to the anterior portion of a patient's chest.
A second electrode placement is referred to as an anterior/posterior arrangement. In this configuration, an anterior pad is placed over the patient's precordium. The posterior pad is placed on the patient's back, behind the heart. The anterior/posterior configuration typically results in a relatively low interelectrode impedance and, hence, high current.
With the defibrillation pads applied to the patient's chest in one of these configurations, the defibrillator/monitor is then used to display and interpret the patient's electrocardiogram (ECG) signals and, if necessary, apply a pulse of energy to the patient's heart to achieve defibrillation.
Although the procedure of attaching electrode pads to the patient's chest and connecting the defibrillator/monitor cable leads to the electrode pads may seem simple and straightforward, in emergency situations errors may occur. Thus, it is advantageous to thoroughly and completely train attending emergency personnel in all aspects of this procedure. One method of training recognized to be effective is the repetitive simulation of emergency situations.
In that regard, prior art training procedures have been developed using ECG simulation signal generators. Typically, such a signal generator produces simulated ECG signals at two electrical connector posts provided on the generator. The trainee attaches the defibrillator/monitor cable leads to the connector posts and, using the defibrillator/monitor, evaluates the signal from the ECG simulation signal generator and determines a next course of action, such as defibrillation.
Although this basic procedure provides a trainee with practice in interpreting ECG signals, it does not allow the trainee to experience other aspects of an emergency situation. For example, no electrode pads are used in this type of training procedure. Thus, the trainee does not have an opportunity to practice the attachment of electrode pads to a patient.
Another approach to training involves the use of a manikin to simulate the patient. The ECG simulation signal generator is located inside the manikin and the electrical connector posts of the signal generator protrude from the chest of the manikin at positions corresponding to the desired electrode placement sites for actual patient use. The trainee then attaches electrode-shaped adhesive pads, provided with holes, to the chest area of the manikin by aligning the holes with the electrical posts.
Although the additional step of applying adhesive pads to the manikin makes the training exercise more realistic, the trainee does not have to identify the proper electrode placement sites. Rather, the proper placement of the electrode pads is prompted by the electrical connector posts on the manikin.
A more refined approach is described in U.S. patent application Ser. No. 462,615, still pending, assigned to Physio-Control Corporation, the assignee of the present application. The training system disclosed in that application includes a physically separated ECG signal generator and manikin. As a result, connector posts are not included on the manikin to assist the trainee in determining the proper electrode placement sites. Although the training procedure performed with this system realistically simulates an emergency setting, it does not allow the trainee to assess the appropriateness of the electrode placements used.
As noted above, however, the correct placement of the electrode pads on the patient is critical, given that the location of the pads greatly influences the effectiveness of the treatment. In view of this observation, it would be desirable to provide a method for training emergency medical personnel in the proper use of electrodes including, in particular, the proper placement of such electrodes.